Composition
Each tablet contains:
Atenolol                       50 or 100 mg

Properties and Mode of Action
ATENO is a hydrophilic selective beta-blocker. It reduces the rate and force of contraction of the heart and decreases the rate of conduction of impulses through the conducting system. Its principal effect is to reduce the response of the heart to stress and exercise. It lacks intrinsic sympathomimetic activity and membrane stabilising properties.
ATENO is not completely absorbed from the gastrointestinal tract and it is not significantly metabolised. It is excreted in the urine and its biological half-life is longer than would be anticipated from its plasma half-life of about 6 to 7 hours.
ATENO diffuses across the placenta and is excreted in breast milk. Only small amounts are reported to cross the blood-brain barrier, and it is only about 5% bound to plasma proteins.

Indications
Management of angina pectoris and hypertension, including hypertension of renal origin.

Dosage and Administration
Hypertenstion
Usual dose is 50 - 100 mg daily given orally as a single dose or in divided doses or up to 200 mg daily if necessary.
Angina Pectoris
Usual dose : 50 - 100 mg daily given orally as a single dose according to the response of the patient.
ATENO tablets can be used with a suitable antihypertensive diuretic to provide a highly effective and convenient antihypertensive therapy.

Precautions
ATENO must not be used in patients with untreated cardiac failure, but may be introduced when the failure has been brought under control. Where congestive cardiac failure appears during treatment with ATENO the drug may be temporarily withdrawn until the failure has been controlled.
In patients suffering from ischaemic heart disease as with other beta-blocking agents, treatment should not be discontinued abruptly. One of the pharmacological actions is to reduce heart rate. If this falls below 55 beats/min., the dose should usually not be increased.
A fall to 45 beats/min. or below is an indication to reduce the dose or to withdraw the drug and start again at a lower dose.
ATENO is excreted via kidneys and care must be taken and dose may be reduced in case of renal failure as follows:
If CCr is 15 - 35 ml / min. : the dose is not more than 50 mg / day.
If CCr is < 15 ml / min. : 25 - 50 mg every other day.
In haemodialysis patients : 50 mg after each dialysis.
Treatment of Overdosage
Excessive bradycardia may be countered by atropine 1 - 2 mg I.V. and if necessary, this may be followed by a beta-stimulant, such as isoprenaline 25 micrograms as a slow intravenous injection.

Drug Interactions
ATENO may enhance the effects of hypoglycaemic agents in patients with diabetes mellitus.
Great care should be exercised in giving ATENO to patients undergoing anaesthesia; and myocardial depressants such as halothane, cyclopropane or ether should be avoided. The effect of other myocardial depressant agents including anti-arrhythmics such as quinidine, procainamide or lignocaine, phenytoin and drugs which interfere with calcium transport such as verapamil may also be enhanced by ATENO.
The effects of ATENO are diminished by beta-adrenoceptor stimulating agents such as isoprenaline; the hypotensive effects of ATENO may be dangerously reversed and the peripheral vasoconstrictor effects enhanced by alpha-adrenoceptor stimulating agents such as noradrenaline or those with mixed alpha and beta-adrenoceptor stimulating properties such as adrenaline. The effects of ATENO may be enhanced by adrenergic neurone blocking agents such as guanethidine or bethanidine or catecholamine - depleting agents such as reserpine, and by diuretics.

Contra_indications
ATENO is contra-indicated in patients with 2nd or 3rd degree heart block.
It is also contraindicated in patients with bronchospasm or obstructive airways disease, metabolic acidosis or hypersensitivity to atenolol.
It should never be given to patients with pheochromocytoma without concomitant alpha adrenoceptor - blocking therapy.

Side effects
Sometimes coldness of the extremities, muscular fatigue, and in isolated cases, bradycardia, sleep disturbances, of the type noted with other beta-blockers, have rarely been reported.
Nausea, vomiting and other gastro-intestinal disturbances, dizziness, hypotension or occasionally paradoxical hypertension and disturbance of vision may occur.

Presentation
ATENO 50 mg Tablets : Box of 2 blisters of 10 tablets each.
ATENO 100 mg Tablets : Box of 2 blisters of 10 scored tablets each.